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Abstract: A selective dimethyl sulfoxide (DMSO) gas sensor based on nanostructured conducting polypyrrole doped with sulfonate anion was constructed. Five sulfonate anions, including HSO3 −, para toluene sulfonate (PTS), dodecyl benzene sulfonate (DBS), dodecyl sulfonate (DS) and 5-sulfo salicylate (SS) were used to dope polypyrrole film. Sulfonated doped polypyrrole samples (PPy-S) have been prepared by polymerization of pyrrole on surfaces of the polyester fibers in the presence of an oxidizing agent. The presence of the dopants in the conducting polymer matrix was verified by FT-IR spectroscopy and the morphology of the resulting PPy-S was analyzed by scanning electron microscopy (SEM). The effects of the dopant type and concentrations on the conductivity and response patterns of the PPy-S as a gas sensor to the different gases were studied. The PPy-S gas sensors had demonstrated fast response time (<1s). The responsivity of the PPy-S gas sensors for various volatile organic compounds (VOCs) was also reported. The PPy-HSO3 exhibit a lowest detection limit to the DMSO and could also be successfully applied as a highly selective sensor for detection of DMSO (DL=30ng). Linearity of calibration curve was observed at the range of 0.1–500μg. [Copyright &y& Elsevier]

Abstract: Polypyrrole (PPy) gas sensor has been prepared by polymerization of pyrrole on surfaces of commercial polymer fibers in the presence of an oxidizing agent. The sensing behavior of PPy gas sensor was investigated in the presence of pyridine derivatives. The resistive responses of the PPy gas sensor to pyridine derivatives were in the order of quinoline>pyridine>4-methyl pyridine and 2-methyl pyridine. The PPy gas sensor was used as gas chromatography (GC) detector and exhibited linear responses to pyridine derivatives in the ranges 40–4000ng. Dispersive liquid–liquid microextraction (DLLME) combined with GC/PPy gas sensor has been developed for simultaneous determination of pyridine derivatives and quinoline. The purposed method was used for determination of pyridine derivatives from cigarette smoke. The GC runs were completed in 4min. The reproducibility of this method is suitable and good standard deviations were obtained. RSD value is less than 10% for all analytes. [Copyright &y& Elsevier]

Abstract: In this work, electrically conductive polymers have been prepared by polymerization of pyrrole on surfaces of commercial polymer fibers in the presence of an oxidizing agent. The resistance of polypyrrole-coated fibers was investigated and related to coating conditions, which was controlled by adjusting the reactant concentrations. The effect of initial treatment with monomer or oxidant prior to polymerization reaction with regards to resistance of sensor was optimized. The morphology of the conducting film on the surface of the fibers was examined by scanning electron microscope (SEM), indicating a strong dependence of the processing conditions. The sensing behavior of polypyrrole-coated fiber in the presence of different volatile organic compounds (VOCs) is studied experimentally. Effects of functional group and polarity of organic molecules on responses of the PPy-coated fiber sensor (PPy-CFS) were investigated. The PPy-CFS had demonstrated fast response time (<1s), high sensitivity for various polar molecules and good reproducibility when reused. The sensitivity of the PPy-CFS for various molecules was in the following order: pyridines>acetonitrile>DMSO>ROHs>aldehydes>ketone>benzene derivatives≫alkanes. [Copyright &y& Elsevier]